Patricia M. Fernberg

Urinary stone formation is common during pregnancy, and many women spontaneously pass their stones. However, clinicians have been loath to use imaging to confirm stone presence in women with unresolved symptoms for fear of exposing the fetus to radiation. 

"You don't know if someone has a stone, and if you condemn them to percutaneous nephrostomy or a stent early in their pregnancy, it can be a huge problem for the rest of the pregnancy," senior author Frederick A. Klein, MD, chief of the division of urology and urologic oncology, told 

 "You have to change the stent every 4 to 6 weeks, and the tube every 4 weeks. Then it turns out they didn't have stones when they came in with renal colic. 

Dr. Klein and colleagues performed a retrospective review focusing on the peripartum outcomes of 46 pregnant women (mean age, 26.2 years) who presented with intractable flank pain suggestive of urolithiasis between November 2004 and June 2006. Most of the women were in their second trimester or later, although three were in their first trimester. All demonstrated negative or equivocal findings on renal sonography, and all underwent low-dose computed tomography (LDCT) at a mean calculated fetal radiation dose of 945 mrads (±548 mrads). 

LDCT identified renal or ureteral stones in 29 women (63%). Consequently, 11 women were managed conservatively, 14 underwent ureteroscopy, and four were implanted with stents and treated postpartum. None of the 29 patients incurred complications during treatment or experienced preterm labor. The balance of the women were successfully managed antepartum. All delivered babies apparently unaffected by exposure to LDCT. 

As a result, use of LDCT is now standard protocol at the University of Tennessee Medical Center for pregnant women presenting with renal colic, said Dr. Klein, who discussed the study data at the AUA annual meeting in Chicago. 

"Our radiologist is really tuned in to LDCT," he explained. "In the old days, [these patients would receive] three shots of intravenous pyelogram, 500 mrad; this was 900 mrad. It's not that big a difference, and the risk is minimal. It's all a function of calculating the radiation dose as low as possible to give us the information we need: the sensitivity and specificity was 90-plus percent. 

"We recommend LDCT during pregnancy when patients are thought to have ureteral colic," Dr. Klein said. "It determines who goes to the OR-and who doesn't." 


Hypertension and obesity have been linked to risk of ureteral calculi. A diet known as DASH can help patients lower their stone risk. Read about it at: 

									http://www.urologytimes.com/DASH

				
Stay current with updated AUA-EAU guidelines for managing ureteral calculi. See: 

									http://www.urologytimes.com/calculi

Articles

Treatment for pregnant women who present with renal or ureteral colic may have become easier for physician and patient alike.

Low-dose CT stone detection: Safe during pregnancy

-Recent research suggests similarities in the etiologic and pathogenetic mechanisms of chronic pelvic pain syndrome (CPPS) and other chronic pain syndromes, such as migraine and irritable bowel syndrome (IBS). The findings may lead to a new treatment approach for CPPS, researchers say. 

Evidence is building from MRI studies of CPPS and research in IBS that visceral hypersensitivity and hyperalgesia in central pain syndromes may depend on the activity of the N-methyl-D-aspartate (NMDA) receptor. Blocking the NMDA receptor would, in theory, quell pain transmission. That theory formed the core of a study presented at the AUA annual meeting by Jordan Dimitrakov, MD, PhD, instructor in surgery (urology) at Harvard Medical School, Boston. 

"To us, there are at least three possible mechanisms in which memantine can be beneficial in CPPS: modulation of glutamate toxicity in the central nervous system, modulation of dopamine transmission or dopaminergic neurotransmission, and modulation of serotonergic neurotransmission in the central nervous system," said Dr. Dimitrakov, who was previously on staff at the Medical University of Plovdiv, Bulgaria, which performed this study. 

The primary outcome was pain relief at 6 months based on the NIH-Chronic Prostatitis Symptom Index (CPSI) pain domain scale; the secondary endpoint was patient-reported improvement in NIH-CPSI quality of life score, global response assessment, and voiding. 

At 6 months, significant improvement in pain, quality of life, and global response assessment score was reported by 77% of men taking memantine compared with 16% of placebo recipients (

<.001). At 1 year, patients in the treatment group reported sustained improvement in pain and quality of life compared with the placebo group. 

No between-group difference was seen on the voiding subscale of NIH-CPSI. 

"That's not surprising, given the fact that most of the patients enrolled at baseline actually reported predominantly pain-related symptoms, rather than voiding symptoms," Dr. Dimitrakov noted. 

Side effects of memantine were minimal; the most frequently reported were dizziness (7%), headache (5%), and tiredness (1%).

 "There are a couple of messages for the clinician," Dr. Dimitrakov said. "The main message is that we need to see a larger study in men with CPPS to evaluate this medication in more detail. The second is that in our hands, this medication appears safe and effective, with minimal side effects. Finally, this is a medication that actually works on a subset of patients. It would be unrealistic to think that a medication is going to be effective in all patients with CPPS." 

Memantine's efficacy and safety are yet to be studied in women, although pilot data from a small, uncontrolled study show similar results. Dr. Dimitrakov and colleagues currently are following 30 women with painful bladder syndrome/interstitial cystitis who have been treated with the drug. He told 

 that results are expected toward the end of 2010. 

Recent research suggests similarities in the etiologic and pathogenetic mechanisms of chronic pelvic pain syndrome and other pain syndromes.

Dementia drug demonstrates efficacy, safety in chronic pelvic pain syndrome

Which approach to radical nephrectomy produces the most durable outcomes in survival and restored renal function: laparoscopy or open surgery? 

Actually, neither approach holds a clear advantage, according to a long-term retrospective review of patient records presented here at the 2006 World Congress of Endourology by urologists at the Cleveland Clinic. They suggest that the choice of procedure is better predicated on what is most appropriate to the patient and the tumor stage, rather than the superiority of either surgical approach.  			

Researchers led by senior author Inderbir S. Gill, MD, examined the medical records of 116 patients diagnosed with localized renal cell carcinoma and who underwent radical nephrectomy from January 1997 through January 1999. In addition, they gleaned data on long-term results from patient charts, radiographic images, and telephone contact with patients and their families. 

Long-term survival parameters included 5-year overall survival, cancer-specific survival, and recurrence-free survival. Renal function outcomes also were scrutinized for the two groups. 

Survival data were evaluated according to clinical stage. No difference was seen between the two groups in patients with clinical T1 and T2 tumors. At median follow-up of 65 months for the LRN group (range, 19-92 months) and 76 months for the ORN cohort (range, 8-105 months), no significant differences in outcomes were observed between the two cohorts. With respect to the long-term benchmarks, 5-year survival rates were 78% and 84% for the laparoscopic and open groups, respectively (

=.24); and the rates of both cancer-specific survival and recurrence-free survival were identical between the two groups: 91% and 93%, respectively (

Little had changed in outcomes for either cohort at 7 years. 

"Cancer-specific survival for clinical T1 tumors in both the LRN and the ORN groups was similar, at 96%," said study co-author J. Roberto Colombo, MD, a research fellow at the Cleveland Clinic's Glickman Urological Institute. "There were no significant differences in overall or cancer-specific survival in patients with clinical T1 and T2 tumors. While cancer-specific survival for patients with clinical T2 tumors after 7 years was 85% in ORN and 61% in LRN, the difference was not statistically significant." 

At 7 years follow-up, survival in the LRN group decreased slightly to 72%, but all other outcomes for both groups were identical to those at the 5-year mark. One patient in the LRN group had a local recurrence and four experienced systemic metastases; no ORN patients had local recurrence, but three patients experienced systemic metastases. 

Mean time to development of metastatic disease in the LRN group was 19 months compared with 14.5 months in the ORN group (

=.52). Four patients in the LRN group (8%) and three patients in the ORN group (7%) died from kidney cancer; eight patients in the LRN cohort and four in the ORN cohort died from other causes. 

Renal function outcomes measured from baseline echoed the trend of the survival outcomes: Serum creatinine levels rose by 33% and 25%, and estimated creatinine clearance fell by 31% and 23% for the LRN and ORN patients, respectively. Four patients in each group developed chronic renal insufficiency, but none died as a result of it. 

Although laparoscopic techniques have been refined significantly since 1999, study co-author Brian R. Lane, MD, PhD, said he did not believe a similar study conducted today would yield different outcomes, with one exception. 

Cleveland-Which approach to radical nephrectomy produces the most durable outcomes in survival and restored renal function: laparoscopy or open surgery?

Open versus lap nephrectomy: Similar long-term outcomes

Understaging of renal tumors on the basis of clinical criteria appears problematic when tumors are morcellated during laparoscopic nephrectomy, according to a Mayo Clinic study presented at the 2006 World Congress of Endourology here. 

"In this cost-conscious world, we're trying to tailor follow-up based on the risks that a patient may have. In this paper, we show that gauging follow-up based on [tumor] size and clinical staging will not accurately predict whether this patient will live or die from his disease," said lead study author Amy E. Krambeck, MD, a urology resident at the Mayo Clinic, Rochester, MN, working with Michael L. Blute, MD, and colleagues. 

The retrospective analysis considered all patients in the Mayo Clinic nephrectomy registry who underwent nephrectomy for organ-confined renal cell carcinoma. Of those 2,676 patients, 195 (7.3%) subsequently were diagnosed with pT3 disease (tumor invasion into the perinephric fat), as confirmed by preoperative radiologic imaging reports. Patients were assigned to one of three groups according to the size of their tumor: 24 (12.3%) had tumors ≤4 cm, 60 (30.8%) had tumors >4 cm and ≤7 cm, and 111 (56.9%) had tumors larger than 7 cm. 

Eight patients (4.1%) were identified from among these groups as having extrarenal invasion on preoperative imaging, and, interestingly, almost half had tumors less than 7 cm in size. The remainder (five of eight) had tumors larger than 7 cm. 

Among patients identified with pT3a renal tumors, approximately half had T1 tumors of 7 cm or less; however, 5% of those who had tumors >4 cm and ≤7 cm had had evidence of extrarenal invasion on their preoperative imaging, Dr. Krambeck explained. 

"It may look like an organ-confined tumor, but you really won't know what you're dealing with until you remove the specimen and pathologically review it," she said. 

Dr. Krambeck noted that the reason some urologists prefer to have tissue morcellated is that it allows the specimen to be removed through a port site and the incision remains small. Leaving the specimen intact requires a longer incision and may extend the patient's recovery time, "but I think, today, in order to do good cancer surgery, you need to be aggressive," she said. 

"Once you morcellate, you lose those tissue points; you no longer can determine if there's renal sinus invasion or perinephric fat or what exactly is involved with the tumor," Dr. Krambeck warned. 

No patient in the study with a T1 tumor less than 4 cm had extrarenal invasion. Thus, the authors concluded, tumor morcellation may exacerbate the already common problem of understaging tumors on the basis of clinical criteria. 

"Confirming clinical staging data with data from the specimen is absolutely necessary to accurately predict outcome in these patients," Dr. Krambeck said. 

Cleveland-Understaging of renal tumors on the basis of clinical criteria appears problematic when tumors are morcellated during laparoscopic nephrectomy, according to a Mayo Clinic study presented at the 2006 World Congress of Endourology here.

Author | Patricia M. Fernberg

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Low-dose CT stone detection: Safe during pregnancy

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Open versus lap nephrectomy: Similar long-term outcomes

Morcellation may worsen staging of renal tumors